1. Field of the Invention
This invention relates to treatment of animal waste.
2. Brief Description of Prior Art
Large confinement and feedlot operations (CAFOs) creates significant environmental problems, including release of raw animal sewage into waste systems, release of ammonia and other odors into the air, release of nutrient rich wastewater into streams and into the groundwater. Combating these problems significantly increases the cost of operating CAFOs'. At the same time, regulations targeting CAFO problems are increasing, reflecting society's desire to reduce the ecological threat from CAFOs.
Prior art solutions to the waste problems of CAFOs have included the controlled application of waste to large areas of farmland. The idea is that the liquid waste acts as a fertilizer. This prior art technique has several problems. The smell often drives down property values and has led to lawsuits. Accidental over application leads to release of the liquid sewage into either streams or groundwater. The effective application needs to include chemical treatments to reduce certain undesired aspects of the liquid sewage such as chemical treatment to reduce phosphorus and ammonia, nitrites and nitrates, for example. To date, phosphorus removal by chemical addition has been a costly alternative for agricultural application. This has been due in part because of the amount of total solids that are typical of manure lagoon effluent.
Some measures of discharge hazards from CAFOs' include: biological oxygen demand (BOD), total suspended solids (TSS), total ammonia nitrogen (NH3−N), nitrate nitrogen (NO3−N), total kjeldahl nitrogen (TKN), ortho phosphorus (PO4−P), total phosphorus (TP), potassium, metals, total coliform bacteria and Escherichia coli. (E. coli), for example.
As will be seen from the subsequent description, the preferred embodiments of the present invention overcome shortcomings of the prior art.
By processing the wastewater through the proposed system the nutrient loading of wastewater will be reduced which in turn reduces the required area needed land irrigation. The recycle of treated effluent back to the storage lagoons will aid in alleviating high concentration of nutrients and total soluble Solids (TSS) that can inhibit biological action. While this is a significant advancement in wastewater processing for CAFOs, the process will allow CAFOs to meet the zero discharge requirements that have been ordered by the federal courts for revised EPA regulations. Furthermore, ETOCS will limit the real risks of breaches in raw wastewater lagoons that often contaminate water resources each year. Enhancement of the landscape and biological diversity with plants and wildlife is another added value of the system.
The addition of the phosphorous removal system will provide supplemental treatment of phosphorus that is not removed via wetland treatment. This management option will assist CAFO operators in controlling this nutrient in effluents. The Eco-Treatment System™ can be fine tuned for land application to meet the nutrient or watering needs of crops. Ultimately, this will reduce the number of acres needed for land application and costs related to maintenance and handling of animal waste.